• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.30 no.4
• /
• pp.39-45
• /
• 2007

The BMAP/M/N/0 queueing system operating in Markovian random environment is investigated. The stationary distribution of the system is derived. Loss probability and other performance measures of the system also are calculated. Numerical experiments which show the necessity of taking into account the influence of random environment and correlation in input flow are presented.

• Proceedings of the Membrane Society of Korea Conference
• /
• 2005.11a
• /
• pp.87-91
• /
• 2005

• Journal of the Ergonomics Society of Korea
• /
• v.34 no.3
• /
• pp.223-234
• /
• 2015

Objective:This study aims to investigate the correlation between office environment satisfaction levels and workers' subjective symptoms by conducting surveys asking office workers to state their subjective symptoms and office satisfaction levels. Background: The increased number of office workers and their work hours have led to new understandings of the importance of office environments including its temperature, humidity, noise levels, lighting, space arrangements, and quality of air. Method: Specific details on office work, office environment, office space satisfaction levels, workplace related symptoms, absence from work, due to workplace-related symptoms, were analyzed based on the survey answers given by 451 office workers who were the subjects of this research. Results: Office workers showed different characteristics of subjective symptoms depending on their gender, age, work experience, and time spent resting and on computers. Also, differences in symptoms were found for workers with different satisfaction levels for office environment (temperature, humidity, noise levels, quality of air, lighting) and office space arrangements (location of monitors, area and display of office space, chairs and desks). Conclusion and Application: Relationship between workers' satisfaction levels with the office environment and their subjective symptoms is expected to be serve as essential data for systematic management of the workplace.

• Journal of the Korean housing association
• /
• v.21 no.3
• /
• pp.87-94
• /
• 2010

The aim of this study was to evaluate the influence of air pollution level in industrial and residential district of Ulsan on resident's evaluation and cognition for indoor environment. The evaluation of air pollution materials (as $SO_2$, $NO_2$, $O_3$, CO, PM10) were investigated to understand the distributional characteristics in survey area, and air quality monitoring data from 2007 to 2009 were used. The data was applied in a realtime measurement of industrial and residential area respected to difference of the pollution level in Ulsan. The questionnaire of this survey for resident's cognition was to find out characteristics on perception of indoor environment and outdoor air quality recognition based on the distinct characteristics of the areas. The results of this study shows that resident's satisfaction at clean level outdoor air and indoor environment were different whether it was residential area or industrial area and outdoor air pollution level has direct influence on resident's satisfaction in indoor environment.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.1895-1905
• /
• 2009

Recently it is required to present a new goal and direction regarding a railroad industrial informatization in order to respond to external change of environment along sharp development technical information communication (ICT), establish a strategic plan for o establish a strategic plan for harmonious developments of private and public sector through harmonious developments of private and public sector and efficient investments on an railroad industrial informatization. Forwarding plans for informatization industrial the existing railroad have been proceeded mainly around informatization of related organization regarding railroads. Study to have read to this established informatization architecture industrial a railroad for establishing deliberate systematic forwarding regarding informatization industrial a railroad of the center functional service a railroad taking charge of. we selected a system sub-of 25 by each fields for this after classifying it to, eight fields such as construction, train driving control, environment, maintenance, logistics, a train, assets management, passenger service.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.27 no.1
• /
• pp.79-92
• /
• 2004

The purpose of this study is to examine the actual condition of environment conscious logistic system which is essential to make material recycling economic society. Environment conscious logistic management which meant simply recycle is tend to promote material reduction, reuse and recycling. We have made case studies about advanced environment friendly logistic system. To examine Korean companies' environment conscious logistic system, we made survey form which is consist of 82 questionnaires and 154 companies have participated for this. And we have analyzed the survey responses. As a result of this study, we propose the way of constructing environment conscious logistic system in Korea.

• Journal of the Ergonomics Society of Korea
• /
• v.28 no.2
• /
• pp.1-8
• /
• 2009

While the operator's working environment employs the digital devices and technology which are not be fully digitalized due to its technical constraints, it has been changed to the hybrid environment in which digital and analog elements are combined. The hybrid environments need to study its characteristics and the guidelines for the proper design and evaluation purpose. This paper describes the characteristics and evaluation guidelines for hybrid environment through studying the characteristics of digital and analog environment based on the related human factor guidelines and literatures. The result of this paper would be applied for the human machine system such as main control room in nuclear power plant working under hybrid environment. And also, it may be applied for the evaluation of the generic human working environment which digital and analog elements are jointly used.

• Journal of the Ergonomics Society of Korea
• /
• v.34 no.6
• /
• pp.609-622
• /
• 2015

Objective: This study aims to investigate the correlation between office and work environment satisfaction levels and workers' musculoskeletal symptoms by conducting surveys asking office workers to state their musculoskeletal symptoms and office and work environment satisfaction levels. Background: The increased number of office workers and their indoor work hours using computers have led to new understandings of the importance of office environment including its temperature, humidity, noise levels, lighting and quality of air, and work environment including monitor arrangement, space arrangement and the functions of desks and chairs. Method: Specific details on office work, office environment satisfaction levels, work environment satisfaction levels, musculoskeletal symptoms, absence from work and treatment due to musculoskeletal related symptoms were analyzed based on the survey answers given by 397 office workers who were the subjects of this research. Results: Office workers showed different characteristics of musculoskeletal symptoms depending on their gender, age, work experience, office hours, break time and time spent on computers. Also, differences in symptoms were found for workers'with different satisfaction levels for office environment (temperature, humidity, noise levels, quality of air, lighting) and work environment (location of monitors, area and display of office space, chairs and desks). ANOVA shows the differences between groups of subjects classified by the experience of work-absences and treatments or pain complaints. Conclusion and Application: Relationship between workers' satisfaction levels with the office and work environment and their musculoskeletal symptoms is expected to be served as essential data for systematic management of the workplace.

• Journal of Environmental Science International
• /
• v.29 no.5
• /
• pp.479-494
• /
• 2020

This study analyses the characteristics of volatile organic compounds (VOCs) emissions from the painting and printing facilities, as well as ambient VOCs at industrial complexes in Gwangju. The major components of VOCs emissions from painting facilities were toluene, acetone, 2-butanone, ethyl acetate, ethyl benzene, o-xylene and m,p-xylene. The printing facilities mostly emitted ethyl acetate, 2-butanone, acetone and toluene. Aromatics (49.9%) and oxygenated VOCs (43.6%) were dominant in painting facilities, while oxygenated VOCs (92.7%) were the largest group in printing facilities. The total hydrocarbon concentration (THC) in printing facilities was approximately six times higher than in the painting facilities. The painting and printing facilities use many solvents. Their THC concentrations differed considerably depending on the type of prevention facilities. To reduce THC, it is necessary to improve the prevention facilities and operating conditions. The dominant species of ambient VOCs in industrial complexes were investigated with toluene, ethyl acetate, 2-butanone, ethyl benzene, m,p-xylene, butyl acetate, o-xylene, hexane and acetone. Factor analysis of ambient VOCs showed that the main sources of the VOCs were organic solvents used in painting, coating, and printing, as well as automobile emissions.

• Journal of Environmental Science International
• /
• v.12 no.2
• /
• pp.133-137
• /
• 2003

The Yellow River delta is an important region where coastal and newly formed wetlands distribute in north China. Based on satellite remote sensing images and GIS techniques, this paper tends to delineate the dynamic changes of newly formed wetland in the Yellow River mouth from 1986.5 to 1996.10. Our results show that the newly formed wetland increased by 24.9 $\textrm{km}^2$ per year. Before 1990. 1 and it decreased by 2.40 $\textrm{km}^2$ per year after that. The northern and southwestern parts of the Yellow River mouth are main positions of decrease and the southern and the estuary parts are main positions of increase. The advancing rate of river mouth extending into the Bo Sea is decreasing obviously. The reason for that is the decreasing of water and sediments in the Yellow River, which caused by the increasing use of water and soil conservation on upper reach.